The exerciser trains at a gymnasium by means of different kinds of adjustable weight loads. The adjustable weight loads are connected to various frames so that the exerciser can select a desired weight load by means of different kinds of lever arms, carriages and transmission means, and train with the weight load using different kinds of handles. The exerciser moves the weight load by means of the handles by constricting the muscle to be trained so that an increasing number of muscle cells in the muscle participate in the accomplishment of the movement. The greater the number of muscle cells made to participate in the accomplishment of the movement, the better the constricting capability of the muscle becomes.
The human body comprises plenty of muscles, and these can be divided into groups on the basis of their way of function. The function of the different muscle groups is to move a certain body part within its own range of motion. The human muscular system functions in two directions, comprising extensor muscles functioning in a direction away from the body and flexor muscles functioning in a direction towards the body. Due to these two different functions, exercise devices, too, are divided into two groups, because there is no exercise device on the market which resists movement in both directions.
In practice, gymnasina are equipped with a plurality of different kinds of devices. This is due to the way of function of the human muscular system and the size differences between individual exercisers, on account of which the push and pull handles have to be positioned at several points in order that everyone could exercise, and that the exercise would be meaningful. Therefore, there are plenty of nearly identical devices in the gymnasina, which devices, however, cannot be used crosswise.
For this reason, the gymnasina require expensive floor area and an enormous number of devices which are intended for training muscles in one direction only and which, in addition, can be used by exercisers of a certain size only. In general, there are several tens or even hundreds of devices. A major part of the devices are out of use for most of the time, because each device is intended for a strictly defined group of users.
Today, the biggest drawbacks of exercise devices are that they are inefficient and uneconomical; the devices cannot at all be used crosswise; and they are intended for a strictly defined group of users; further, temporary auxiliary structures are highly dangerous. These problems are mainly due to the fact that the exercise can be carried out in one direction only; since the pull handle is stationarily positioned, with little or no possibility for adjustment, it is possible by means of the device to carry out a single exercise in one direction only. If the devices are provided with temporary auxiliary structures uncompatible with the device, it may be possible that a few similar exercises can be made therewith, or a person of unsuitable proportions may be able to use the device.
In carriage systems, the initial weight load consists of the weight of the carriage and the different handles, so that the lowest weight load is usually far too high for beginners and particularly for women.
In lever systems, the weight load is unreal. It is necessary in the device to use oversized weight loads, which increases considerably the manufacturing costs of the weight load and the frame. In many cases, the lever arm requires even a double weight load.
A wire, chain, belt or some other transmission means enables the weight load to be pulled in the device in different directions from different heights, but it does not allow the weight load to be pushed.
The use of oversized weight loads used for one purpose only, heavy carriages, uneconomical lever systems and unreliable cords, wires and bulky, freely hanging chains is difficult and expensive, and requires a lot of room.